It depends whether the employer's plan is self insured or not. If the employer is self insured, the employer need not keep you on the health plan. If the employer is fully insured (i.e., not self insured), the employer likely must keep you on the plan. It is important to understand the status of the employer's health insurance who employed your husband at the time of your divorce. Note that I am not a matrimonial lawyer and I am just answering this based on personal experience (and finding out the hard way). Hopefully, a matrimonial lawyer on Avvo will respond - there are many good ones.
Mr. Thomas is licensed to practice law in Massachusetts. This response is not legal advice and does not create an attorney/client relationship. This response is in the form of legal education and is intended to provide general information about the matter within the question. Often, the question does not include significant and important facts and timelines that, if known, could significantly change the reply. Mr. Thomas strongly advises the questioner to confer with an attorney to make sure he or she gets all relevant information to make informed decisions about the subject matter.
Attorney Thomas is on the right path. The key is understanding the terms of the health insurance plan. I suggest you contact a local attorney.